Picture-projecting apparatus



c. F JENKINS.

PICTURE PROJECTING APPARATUS. APPLICATION FILED OCT. 1] I916.

' 1,327,280. A Patented Jan. 6,1920.

2 SHEETS-SHEET I.

C. F. JENKINS.

PICTURE PROJECTING APPARATUS.

APPLICATION FILED OCT-17,1916.

1,327,280. A Patented Jan. 6, 1920.

2 SHEETS-SHEET 2; a.

INSULIIT/ON \\\\\\\\\\\\\\\lIlllHlIlHllIllllllllIl ms a4 1 1 7/0 ImrrEDSTATES PATENT OFFICE.

CHARLES FRANCIS JENKINS, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGN ORTO THE GRAPHOSCOPE COMPANY, OF WASHINGTON, DISTRICT OF COLUMBIA, ACORPO- RATION OF DELAWARE.

PICTURE-PROJECTING APPARATUS.

Specification of Letters Patent.

To all whom it may concern:

Be it known that I, CHARLES FRANCIS JENKINS, a citizen of the UnitedStates, and resident of Washington, in the District of Columbia, haveinvented certain new and useful Improvements in Picture-Pro ectingApparatus, of which the CEOllOWlIlg 1s a specification, reference beinghad therein to the accompanying drawing.

This invention relates to apparatus especially intended for pro ectingpictures by means of an are light. The princ pal objects are to provide,in a casing which can be adjusted bodily parallel to the beam of light,an arc light which can be adjusted bodily, within the casing, indistance from the condensing lens, and having means whereby one or moreof the carbons can be adjusted with certainty by a single movement,according to the way the parts are seized by the hand.

In the accompanying drawings,

Figure 1 is a view showing the apparatus partly in axial verticalsection.

Fig. 2 is a plan view of the same devices.

3 is a section on the line 3-3, Fig. 2.

Fig. 4 is a section on the line 4-4, of Fig. 2.

In these views, 1 represents a table upon which is a standard 2 mountedfor longitudinal adjustment in a slot This standard passes upwardthrough a slot 5. in the bottom of a casing 6 in the walls of which arefixed parallel rods 7 in a horizontal.

plane. Within the casing the standard supports a rigid spider .8, Figs.1 and 2, having four arms, two of which support each of the rods bymeans of bearings in their upturned ends and thus carry the casing. Uponthe rods is mounted a saddle 9 carrying a heavy vertical insulatingplate 10 transverse to the rods. A screwll, rotating without advance inthe casing, engages the saddle and adjusts it along the rods 7. Threecarbons 12, 13, 14 are shown, the first, passing through an opening inthe plate 10 in the axial line of the beam of projecting light andresting in a V-shaped trough 15 supported by a bell-crank 16 adjustablysecured to the plate 10 and connected to one electric terminal 17 Thecarbon 12 isheld in the trough by the sharp corners of disks 18 ofemery, other forms of corundum, -or analogous material having similarlyhard and sharp particles capable of effectively engaging light carbonsfixed on a rotaryshaft -19 mounted in bearings 21 upon a bar pivoted atthe center of its circular end portion 20, to the plate 10 and drawntoward the trough by a spring 22. The bell crank 16 is pivoted to theplate 10 near its angle and its end above the terminal 17 is proPatented Jan. 6, 1920.

vided with a stud which passes through the 1 plate 10 in a suitable slotand is clamped in any desired position by a nut 16,Fig. 2. By

loosening this nut the bell crank is permitted to swing and press eithera large or a small carbon against the disks 18, and the bell crank maythen be locked by the nut 16. By this expedient only slight adjustmentof the disks 18 is ever necessary. The carbons 13, 14 in the horizontalplane of the carbon 12 diverge oppositely from the axial line thereof,and are pressed against similar L emery disks 23, 24 mounted upon shortvertical shafts 25, 26, by pivotally mounted troughs 27, 28 and springs29, 30,-c'urrent being brought tothe troughs by conductors 40, 41entering the casing at 42. These devices like those for the carbon 12are supported fromthe plate 10 upon rigid studs 10', Figs. 1 and 2. Theemery disks 23 are rotated by a shaft 31, having a milled head 32 andacting through bevel gears 33. The disks 24 are similarly rotated by' ahollow shaft 34 concentric with 31 and acting' through bevel gears 35,this hollow shaft having a milled operating head 36 alongside the head32 but slightly separated therefrom, and the disks 18 are rotated by asecond hollow shaft or sleeve 37 inclosing the hollow shaft 34 andacting through sprocket wheels 38, 39 connected by a chain belt 43, thissleeve being rotated by a milled head 44 alongside the heads 32 and 36.The

three concentric shafts pass out through a slot at 6, F ig. 2, in thecasing andtheir external milled heads are at such distance apart thatanyone or more may be engaged by the fingers and rotated, one, two orall the shafts being rotated by a single movement of the fingers.

The lens holder 45 contains no novelty herein claimed.

What I claim is:

1. For holding a carbon and adjusting it longitudinally, a trough memberfor resting against one side of the carbon, a second member comprisingtwo disks of corundum separated to a distance less than the carbonsdiameter, and resting against the opposite side of the carbon, a sprlngurging one-of the members toward its com anion, and means for manuallyrotating t e disks.

2. The combination with a carbon of two other carbons in the plane .ofthe first,

3. The combination with a carbon of two other carbons, in the plane ofthe first, diverging from its end and forming arc gaps therewith, ofmeans whereby the hand of the operator by a single movement may 1axially adjust one, two, or all the carbons,

as desired, and means for at will moving 20 all the carbons along theaxial line of one of them.

In testimony whereof I hereunto aflix my signature.

- CHARLES FRANCIS JENKINS.

